Mechanism of catalytic cycloboration of α-olefins with boron trichloride: the synthesis of hardly obtainable boriranes and the mechanistic DFT study of transmetalation of titanacyclopropane intermediates

Abstract

A theoretically justified mechanism of transmetalation of 2-alkyl substituted titanacyclopropanes with BCl₃ is proposed based on the DFT calculations of the thermodynamic and activation parameters of possible reaction pathways. Based on the data obtained, phenyl- and alkyldichloroboranes were proposed to be used as transmetalating agents along with BCl₃ in the catalytic cycloboration in the presence of Cp₂TiCl₂ and Mg metal. It was shown that the barely accessible 1-phenyl-2-hexylborirane can be synthesized using PhBCl₂.